465B cleaning

[bitbanger]

Hi Folks -

Long time lurker; first post in a while. 

I have a trusty Tek 465B that has been with me for nearly 10 years now. It has always been kept in a mostly dust-free, A/C'd lab, but the knobs are starting to get a little scratchy. Specifically, the scale illumination and channel intensity controls, which were once working perfectly, have become twitchy - all or nothing for the scale illum., and getting there with the intensity.

Unfortunately the 465 is only powered up/warmed up a few times a year, sometimes intentionally, since purchasing a DSO,

Anyway, I would like to hear your opinions (as I'm sure there are varying) on what the safe and proper method of maintaining rotary contacts and pot wipers for this generation of equipment is. There seems to be a dizzying array of cleaners, lubricants, etc on the market these days, and I know just enough to know that some types can do more harm than good.

Best,
Jamie

[wazzokk]

I also have one of these scopes, I have never cleaned the contacts but if you search on "TekScopes@yahoogroups.com" forum I know I have seen it discussed there.
Regards Dave

[HiTech]

Avoid cleaners that leave an oily residue like DeOx-it. Stick with something like CRC contact cleaner that dries clean. The DeOX-it is for stubborn cases.

[robrenz]

IMO
 
Step 1 Apply DeoxIT D100L to clean, cycle thoroughly.
Step 2 IPA wash to remove all the G100L
Step 3 Apply DeoxIT G100L to seal and lube, cycle thoroughly.
Step 4 Wipe all G100L off the contacts with clean wiper or paper. Don't use any solvents, you want a light film to remain.

In some cases I accomplish step 4 with high pressure compressed air only.

FWIW

[robrenz]

This short thread contains more info and links to support my opinion.

[David Hess]

For potentiometers and any switches which have a wiping action, besides cleaning a lubricant needs to be left on the surfaces.  They make combination contact cleaner and lubricants for this sort of thing.  I like using poly phenyl ether lubricants for this because they do not creep but the alternatives which use silicon oil work well also.

On the cam switches, you want no lubrication and cleaning needs to be done carefully so as not to abrade the contact surfaces.  Drawing a strip of clay free paper soaked in IPA through the contacts while they are closed works well.

[niflheimer]

i don't like using silicone oil since it tend to leave a film that's pretty much impossible to remove on any kind of fiberglass board . As david said , I do like the PPEs - and you can remove them easy enough with ipa or other solvents.